1. Field of the Invention
The present invention relates to the construction of a winter windshield wiper for a motor vehicle and more particularly, to an improved winter windshield wiper having at least one horizontally elongated, contoured and flexible vane for effectively cleaning and wiping the convex surface of the windshield glass of a motor vehicle in a cold climate or the winter time, and extending the operation life of the windshield wiper.
2. Description of the Related Art
Generally, various types of windshield wiper frames for a windshield wiper assembly are well known. Such windshield wiper frames include a bridge, a pair of primary yokes pivotally connected to the bridge, a pair of secondary yokes pivotally connected to one end of each primary yoke, a mounting stay mounted on the other end of each primary yoke and mounting stays mounted on each end of the secondary yokes. However, such conventional art wiper frames suffer from poor cleaning performance by the windshield wiper blade due to inadequate pressure on the windshield glass.
In order to improve cleaning performance, one known windshield wiper frame as shown in FIG. 1, is equipped with a bridge having a pair of vanes extending up from the rear walls thereof. However, this wiper frame suffers from a number of problems. For example, as air flowing past the vehicle presses down on the pair of vanes, the entire upper portion of the wiper frame is also pressed down toward the glass, causing the entire frame to pivot slightly. Therefore, the lower portion of the wiper frame, and the wiper blade itself may be lifted slightly away from the glass, thereby preventing the wiper blade from effectively cleaning the convex surface of the windshield glass. This pivoting can result in decreased operational life of the wiper arm. In addition, the known bridge with vanes lacks openings disposed on the top of the bridge. These openings are needed to maintain the pressure balance on the two sides of the bendable lip of the blade so as to achieve an effective cleaning operation.
The present inventor has owned U.S. Pat. No. 5,311,636 disclosing a windshield wiper frame for use in a windshield wiper assembly for motor vehicles which includes a pair of primary yokes, and a bridge member pivotally connected to the pair of primary yokes and having at least one elongated vane which extends downwardly and at a slant from the front wall of the bridge member. This windshield wiper assembly can efficiently wipe the convex surface of the windshield glass and extend the operational life of the windshield wiper assembly. However, this windshield wiper frame may not be completely effective in the winter time or where there is heavy snow.